New aspects of airborne MTI

Abstract

The performance of adaptive moving target indication (MTI) filters for use on airborne radar platforms is addressed. Clutter returns received by a moving radar exhibit a Doppler shift which depends on the platform velocity, on the cosine of the angle between the flight axis, and the position of the individual scatterer. Therefore, the platform motion causes clutter echoes to be Doppler broadband, with the bandlimits determined by the platform speed. Efficient clutter suppression requires platform motion compensation or, more general, two-dimensional MTI filters which operate in time and space. In the spatial dimension echo signals may be subject to decorrelation due to the system bandwidth. Such effects are discussed. The results are of particular importance for high-resolution airborne search radar, including real and synthetic aperture applications.<>